Known from prior art are fixed wings with non-planar wing tip devices or wing tip shapes that differ in terms of their geometric shape and structural size so as to improve the aerodynamic efficiency of the fixed wing.
Known from DE 101 17 721 A1 is a wing tip extension for a wing with an upper and lower surface, along with a leading and trailing edge, with geometries of a kind that produce a continuous increase in the local dihedral angle, a steady increase in the sweep of both the leading edge and trailing edge, and a continuous decrease of the chord of the wing tip extension between a connection area for joining with the wing and the tip of the wing tip extension, and that cause the wing tip extension in the connection area to be essentially continuously in tangency joined with the wing. The literature offers a plurality of fixed wings with various wing shapes or winglets provided primarily to reduce aerodynamic drag, and hence to increase aerodynamic efficiency. Wing tip shapes can be defined as being part of the process of designing a new fixed wing or overall aircraft, or retrofitting an already existing aircraft with such a wing tip shape. In the latter case, the present wing tip shape geometry is replaced by another. In both instances, while designing the wing tip shape, the increase in aerodynamic efficiency must be balanced against any changes, often increases in the structural load, which is often expressed in a simplified manner using the wing root bending moment, and all resultant consequences with regard to aircraft weight. The evaluation of various tip shapes can yield different results due to the respective design scenario and boundary conditions.
Also known from general prior art is a so-called wing tip fence (WTF), which is comprised of two similarly dimensioned components and extends upward and downward, nearly perpendicular to the wing. To optimize the flow quality on the wing, wing tip shapes have been realized with continuously smooth transitions for the sweep and dihedral between the outer end of the main wing where the wing tip shape is situated and the wing tip shape.